A roof system of this type is known from DE 10 2008 017 526, B3. The known roof system is provided for a passenger vehicle and has a roof opening which can be closed by a liftable and longitudinally movable cover. The cover is provided on both of the opposite longitudinal sides thereof with a web guide which is fastened to the cover and is mounted in a respective slider unit. The slider unit is coupled to a deployment lever which is mounted pivotably on the roof side. The slider unit comprises two rotary sliders which are spaced apart from each other, each have a guide slot for receiving the web guide and are matched in the rotational position thereof to a curved profile of the web guide.